Reset control for DC-DC converters: an experimental application

© 2019 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Power converters in grid connected systems are required to have fast response to ensure the stability of the system. The standard PI controllers used in most power converters are capable of fast response but with significant overshoot. In this paper a hybrid control technique for power converter using a reset PI + CI controller is proposed. The PI + CI controller can overcome the limitation of its linear counterpart (PI) and ensure a fast flat response for power converter. The design, stability and cost of feedback analysis for a DC-DC boost converter employing a PI + CI controller is explored in this work. The simulation and experimental results which confirm the fast, flat response will be presented and discussed.Peer ReviewedPostprint (published version

Unity of pomerons from gauge/string duality

We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory of a 5-d string theory. It describes the exchange of higher spin fields in the graviton Regge trajectory that are dual to glueball states of twist two. For a specific holographic QCD model we describe Deep Inelastic Scattering in the Regge limit of low Bjorken x, finding good agreement with experimental data from HERA. The observed rise of the effective pomeron intercept, as the size of the probe decreases, is reproduced by considering the first four pomeron trajectories. In the case of soft probes, relevant to total cross sections, the leading hard pomeron trajectory is suppressed, such that in this kinematical region we reproduce an intercept of 1.09 compatible with the QCD soft pomeron data. In the spectral region of positive Maldelstam variable t the first two pomeron trajectories are consistent with current expectations for the glueball spectrum from lattice simulations

Soft Pomeron in Holographic QCD

We study the graviton Regge trajectory in Holographic QCD as a model for high energy scattering processes dominated by soft pomeron exchange. This is done by considering spin J fields from the closed string sector that are dual to glueball states of even spin and parity. In particular, we construct a model that governs the analytic continuation of the spin J field equation to the region of real J < 2, which includes the scattering domain of negative Maldelstam variable t. The model leads to approximately linear Regge trajectories and is compatible with the measured values of 1.08 for the intercept and 0.25 GeV$^{-2}$ for the slope of the soft pomeron. The intercept of the secondary pomeron trajectory is in the same region of the subleading trajectories, made of mesons, proposed by Donnachie and Landshoff, and should therefore be taken into account.Comment: 7 pages, 5 figures. V2 : The paper has been expanded to provide more details of the model and results. Added two new figures and two new references; corrected typo

Verb Production and the Semantic Interference Effect

In three experiments, we explored the semantic interference effect in verb production with the picture-word interference paradigm. Experiments 1 and 3 addressed whether there is an effect of semantically related distracters on gerundial verb production; In Experiment 2, we explored the effect in naming verbs in sentence production and the third person singular form. The semantic interference effect was found in two of the three experiments. However, the effect was inconsistent when transitive and intransitive verbs were analyzed separately. The results are discussed in the context of models of the semantic interference effect in lexical access

Controlling ligand surface density on streptavidin-magnetic particles by a simple, rapid, and reliable chemiluminescent test

International audienc

Pérmico continental en España

[ES] Los conocimientos que hasta el momento se poseen, indican que en España el Pérmico está representado por el «Autuniense» (Rotliegendes Inferior) en facies grises características y por formaciones rojas que son atribuidas al «Saxoniense» (Rotliegendes Superior). El Pérmico Superior sólo ha sido citado en muy escasos puntos. En general, está constituido por series detríticas, cuyo tamaño va desde la arcilla, hasta conglomerados de gruesos bloques. Frecuentemente se intercalan rocas volcánicas de diversos tipos. Su potencia es muy variable, pudiendo llegar a alcanzar espesores de más de 2.000 m. Su deposición se realiza en cuencas continentales condicionadas normalmente por la tectónica tardihercinica. Todas sus características, así como los problemas que plantea su cronoestratigrafia son muy similares a los del Pérmico de Europa Occidental.[FR] Les connaissances aujourd’hui acquisses indiquent quen Espagne, le Permien est répresente par «l’Autunien» (Rotliegendes Infericur) en facies gris characteritiques et par des formations rouges atribuées au «Saxonien» (Rotliegendes Superieur). Le Permien Supericur a été identifle seulement dans quelques points. En general, les séries sont constituées par des seditnents détritiques, des les argiles juqua les conglomerats; frequentment on trouve des passées volcaniques de type divers. Sa puissance est tres variable, jusqua 2.000 metres maximum; sa deposition prend lieu dans bassins continentaux controlés normalement par la tectonique tardihercynienne. Ses characteritiques et ses problemes sont tres similaires a ceux du Permien de lEurope Occidentale.[EN] The present data show that the Spanish Permian is represented by the «Autunian» (Lower Rotliegendes) in a typical grey facies and redbeds similar to the «Saxonian» (Upper Rotliegendes). The Upper Permian has been found only in a very few points. In general it is made of detrital series, from clays to conglomerates; some volcaníc levels are found. Tickness is very variable, up to 2.000 meters. Sedimentation takes place in continental basins, tectonically con troled 1w the tardihercynian pbases. Their caracteristics and problenis are similar to the ones of Western European Permian.Peer reviewe

Grid voltage regulation using a reset PI+CI controller for energy storage systems

© . This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Hybrid controllers are capable of improved performance over their linear counterparts. In particular, reset controllers like the PI+CI are capable of fast flat response for lag dominant plants. Grid connected power converters especially interfacing energy storage systems to grids are required to have fast response to varying load demands to ensure minimum variation in grid parameters. Application of PI+CI controllers in such systems can improve their performance. In this work the improvement brought about by use of PI+CI controller employed for energy storage system power converters is highlighted by comparing it with PI controller based system under load variations. A DC microgrid with Fuel cell-supercapacitor based storage elements are considered here. The design criteria and simulation results are presented here.Peer ReviewedPostprint (author's final draft

Proceso de tratamiento para la recuperación de oro en el asentamiento minero artesanal de Misky, Perú

La población de Misky, Arequipa, Perú, con alrededor de 1000 habitantes, vive exclusivamente de la minería artesanal de oro. Se trata de un yacimiento de tipo mesotermal de edad cretácica. Las características del yacimiento hacen que éste únicamente presente interés para la minería artesanal. El oro extraído en estas minas es procesado mediante la utilización de mercurio, el cual produce severos daños medioambientales y a la salud humana. El mineral que contiene oro es molido mediante la utilización de quimbaletes, que además concentran el oro mediante la producción de una amalgama con el mercurio. Posteriormente esta amalgama es procesada en una retorta para separar el oro. Mediante este sistema se recupera una cantidad de mercurio no superior al 80% del utilizado, el resto es emitido al medioambiente. Las aguas que se encuentran en la población de Misky y zonas circundantes contienen una concentración de mercurio en niveles superiores a los permitidos por la OMS. Se propone la realización de una concentración del mineral de oro previamente al empleo de los quimbaletes para reducir la cantidad de mercurio utilizado y la utilización de mercurio activado. También se sugieren modificaciones en la retorta utilizada, similarmente a otros modelos comerciales con las que se consigue una recuperación de mercurio mucho más elevada que con la retorta actualmente existente en Misky.Postprint (published version

Vacuum Insulation Panels: Thermal Bridging Effects and Energy Performance in Real Building Applications

Due to their very low thermal conductivity, Vacuum Insulation Panels (VIPs) have recently seen a fast development and an increasing penetration in building thermal insulation market. However, there is still a lack of knowledge about their performance when actually applied in buildings. In fact, the thermal bridging effects that occur in VIP junctions are not easily evaluable while produce a reduction of the global thermal performance. In this paper, the linear thermal transmittances related to VIP junctions considering different joint materials between VIPs panels and different wall configurations were assessed through a 2D numerical analysis. Finally, through a quasi-steady state simulation, a parametric building case study was analysed, with the aim to evaluate the influence of the thermal bridging effects on the overall building energy need. The results shows that the thermal bridging effect due to VIPs assemblies have not a negligible influence on the overall building energy performance